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Packages and symbol tables

by johnnywang (Priest)
on Dec 01, 2007 at 09:37 UTC ( #654294=perlquestion: print w/replies, xml ) Need Help??
johnnywang has asked for the wisdom of the Perl Monks concerning the following question:

(This is a continuation of XML::Generator problem in mod_perl, now I got rid of all the none relevant info)

I have a module

package Foo; package Foo::Bar; use base 'Foo'; package Foo::Bar::Test; use base 'Foo::Bar'; 1;
My problem is that the above module loads ok in command line perl, but it fails in mod_perl (failed on the last "use base 'Foo::Bar'", it can't find the class Foo::Bar)

Is there a way to find out what symbols/packages have been loaded before that failed call? I tried the following:

package Foo; package Foo::Bar; use base 'Foo'; print "$_ => $Foo::{$_}\n" foreach keys %Foo::;
which in commandline produces:
Bar:: => *Foo::Bar:: VERSION => *Foo::VERSION Bar:: => *Foo::Bar:: isa => *Foo::isa VERSION => *Foo::VERSION
but in mod_perl, it produces:
Bar:: => *Foo::Bar:: <br> VERSION => *Foo::VERSION <br>
I guess my question is whether this is the right way to see whether the "Foo::Bar" package is loaded, and why mod_perl behaves differently? (perl 5.8.0, mod_perl 1.29, apache1.3.3)

In my real situation, the package is XML::Generator. To complicate the things further, I have another "identical" installation of perl/mod_perl/apache, where this works ok. I guess I'm trying to find out how to figure out what the difference is.

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Re: Packages and symbol tables
by Joost (Canon) on Dec 01, 2007 at 14:16 UTC
      Thanks Joost, your suggested change to use @ISA solved the problem (although I'm now on to the next one!) care to explain the thinking in your message?